HTTP 202 Accepted vs 428 Precondition Required
HTTP 202 (Accepted) is a 2xx Success response, while 428 (Precondition Required) is a 4xx Client Error response. 202 indicates that the request has been accepted for processing, but the processing has not been completed. The request might or might not eventually be acted upon. In contrast, 428 means that the server requires the request to be conditional (e.g., include If-Match header) to prevent lost updates.
Description
The request has been accepted for processing, but the processing has not been completed. The request might or might not eventually be acted upon.
When You See It
For async operations like batch jobs, email sending, or background tasks that take time to complete.
How to Fix
Poll the provided status URL or wait for a callback/webhook.
Description
The server requires the request to be conditional (e.g., include If-Match header) to prevent lost updates.
When You See It
When an API requires optimistic concurrency control via ETags.
How to Fix
Fetch the resource first to get its ETag, then include If-Match in your update request.
Key Differences
202 is a 2xx Success response, while 428 is a 4xx Client Error response.
HTTP 202: The request has been accepted for processing, but the processing has not been completed. The request might or might not eventually be acted upon.
HTTP 428: The server requires the request to be conditional (e.g., include If-Match header) to prevent lost updates.
You encounter 202 when for async operations like batch jobs, email sending, or background tasks that take time to complete.
You encounter 428 when when an API requires optimistic concurrency control via ETags.
When to Use Which
For 202 (Accepted): Poll the provided status URL or wait for a callback/webhook. For 428 (Precondition Required): Fetch the resource first to get its ETag, then include If-Match in your update request.